Exiting only port 80

[Roger Dingledine]

On Mon, Apr 30, 2007 at 09:53:27PM +0100, Mike Cardwell wrote:
> Am I right in thinking that most people use Tor for web browsing, over
> ports 80 and 443? And am I right in thinking that most of tors bandwidth
> is used up by a minority of users, using services that require much 
> higher amounts of bandwidth, such as ptp traffic?

I think those are reasonable assumptions. A few people have done informal
studies, and they found that the majority of _requests_ are for web
browsing, and the majority of _bytes_ are for higher-bandwidth protocols.

> If I am right, wouldn't the majority of the tor user base be better
> served if a collection of exit nodes only exited port 80 and 443
> traffic? Does that have privacy implications? I initially thought
> I should configure up my node to exit all traffic except for certain
> ports, but after giving it more thought, it seemed the wider network
> would be better off having more available http/https traffic.

Could be. I don't think it will be as effective a solution as you hope,
though -- more and more of the Internet is travelling over port 80 these
days, due to firewall restrictions, filters, and people taking steps
like the one you propose. :) It's not an arms race we can easily win,
so I'm not that enthusiastic about starting it.

--Roger